.NET softwired

Adding a hardware button keypad to the AMI board

One of the things you notice when you receive the AMI board, is that there are no hardware buttons on the board.

This article shows you how to connect hardware buttons so you can get started testing all the sample WPF applications that use the navigation buttons and of course write your own programs.

Please note that AUG Elektronik already have a nice looking ready made solution as an add-on board for the AMI. This add-on board have a number of extra features and you can read about it here.

If you feel like making your own simple keypad, then keep reading.

AMI board

The AMI board from the Austrian company AUG Elektronik, is in my opinion more than just a prototyping/development board like you have seen from other vendors. The board is ready to be used and incorporated in your own products.  

When you develop software for this board, you will most definitely need a hardware keypad with a basic set of buttons, like the up/down/left/right/select buttons. But you have to add this yourself or buy the add-on board from AUG. It is however very easy to attach a set of buttons to the board, as all GPIO pins are available on a set of Micro-Match connectors on the back of the board.

Navigation buttons and connectors

What you need is 5 buttons of good quality, a piece of stripboard/vero board to mount the buttons on and some wire. When you receive the box with the AMI board you get  a set of Micro-Match male connectors that connects to the board. Use these to connect the buttons.

A schematic diagram of the wiring will look like this:


The AMI board microcontroller uses internal pull-up resistors for the input pins, so a diagram with the detailed connections are as this:

The codes shown as "P5.9", refers to the Micro-Match connector on the AMI board, where P5 is the name of the connector and the ".9" means "pin 9". So "P5.9" means "Connector P5, pin 9".  The references I have used are the same as you can find in the technical manual from AUG Elektronik.

Remember to connect the ground connection, which can be found on P4.2

Click on a picture to see it in a larger version.


Additional buttons

In my version of the keypad, I have mounted more than the 5 navigation buttons (although not yet wired). This is only because I found it easier to mount all buttons now when I had heat on my soldering iron and as there are more GPIOs to be used... As you can also see I have used buttons with built-in LEDs. It is always good to be prepared for the future!

Have fun